In a wireless communications system, to meet a growing requirement of high-bandwidth high-speed mobile access, the release 9 (Release 9 ) protocol of the 3rd-Generation Partnership Project (the 3rd Generation Partnership Project, 3GPP for short) wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA for short) includes a downlink dual-carrier feature and an uplink dual-carrier feature, that is, downlink transmission using a High-Speed Downlink Shared Channel (High-Speed Downlink Shared Channel, HS-DSCH for short) and uplink transmission using an Enhanced Dedicated Channel (Enhanced Dedicated Channel, E-DCH for short) can be performed simultaneously on two carriers. In R10 and R11, downlink 4-carrier and 8-carrier features are introduced and downlink throughput is further improved.
In a multi-carrier system, an anchor carrier exists among the multiple carriers and other carriers are secondary carriers. The anchor carrier is activated by default and cannot be deactivated, whereas the secondary carriers may be activated or deactivated. In the prior art, a base station may control activation and deactivation of secondary carriers of a user equipment by using a High Speed Shared Control Channel order (High Speed Shared Control Channel order, HS-SCCH order for short) at a physical layer.
However, if a version of a user equipment is inconsistent with a version of a base station serving the user equipment, the user equipment activates or deactivates a carrier in error, thereby affecting uplink and downlink communication of the user equipment.